There are some quite sane comments in a report of a conference held a couple of months ago as part of Princeton's project on US "National Security in the 21st Century" (and recently published on the web) .
On "Europe", for example, there were two schools of thought: pessmists and optimists.
"[The pessimists] argue that Europe will be less able and less willing to fulfill its historic role as America's key ally, pointing to a declining and aging population, a low tolerance for immigration, deeply embedded resistance to necessary root and branch reform, slow economic growth, political stagnation, and a refusal to seriously engage in defence modernization. Their bottom line is that while the U.S. should seek good and fruitful relations with Europe, it should not kid itself that [Europe] can ever again be the robust and loyal partner that it once was.
The optimists argue that prophecies of Europe's decline are greatly overstated....Europe has a) over 100,000 troops overseas, b) supported every U.S. military actitivity since the end of the Cold War except Iraq, c) complements the U.S. in important ways, d) exercises considerable soft power, e) expanded and continues to expand the zone of democracy eastwards, f) is a pioneer of international aid, and g) has a compelling social model that appeals to large parts of the world."
As the report almost says, the reality may be a mix of both (plus some things it doesn't mention).
Recent events in France would seem to add to the pessimist's case. But France is not all of Europe. Some of those among the most critical of the state of France, such as Nicola Bavarez, author of La France qui tombe, emphatically distinguish it from other countries. See: Why a sick France needs a true cultural revolution. Is he right?